The Washington University Training Program in Principles of Pulmonary Research provides predoctoral and postdoctoral research training in the disciplines of respiratory cell and molecular biology, genetics, immunology, microbiology, pharmacology, physiology, structural and chemical biology and biochemistry, and developmental biology. The Program emphasizes scientific approaches critical to understanding mechanisms of lung disease with components of fundamental, translational, and clinical research. The postdoctoral portion of the training program enables physicians training in pulmonary and critical care medicine to learn how to perform state-of-the-art scientific research in concert with Ph.D. trainees from a basic science background. In addition, predoctoral trainees in the M.D./Ph.D. and Ph.D. programs in the Division of Biology and Biomedical Sciences are a vital component of the Program. The aim of the Program is to promote the scientific growth of trainees so they may enter academic pulmonary medicine with the skills needed to study problems relevant to understanding respiratory diseases. The primary and support training faculty consists of 54 full-time members of the Departments of Biostatistics, Biochemistry, Bioengineering, Chemistry, Cell Biology/Physiology, Genetics, Internal Medicine, Molecular Biology/Pharmacology, Microbiology, Pathology/Immunology, Pediatrics, Physics, Radiology, and Surgery. Current research projects span the gamut of respiratory science. The nature of the faculty and the scientific projects ensures a well- organized, multidisciplinary interface of pulmonary researchers with basic scientists. The program is designed to provide trainees with an intensive laboratory or clinical research experience supplemented by graduate coursework and research conferences. In the laboratory, trainees utilize cutting-edge approaches relevant to their particular investigative area. Basic science courses and conferences are used to build skills in evaluating scientific literature, identifying important questions, designing experimental approaches, and organizing, analyzing, and presenting scientific data. Each trainee is under the supervision of a mentor and other supervisory experts as needed for the specific project, and the Program closely monitors trainee and mentor performance. These mechanisms serve to ensure high level trainee experiences in research techniques, lecture presentation, manuscript preparation, grant application, and mentoring.